1. Field of the Invention
The present invention concerns a device for observing discrepancies between the upper and lower jaw.
2. Description of the Related Art
The relative positions between the upper and lower jaws may change depending on the situation where the jaws are in a mutually centric position, i.e., with the cusps of the teeth not fitting together in a resting position, or the situation where they are in a position with the cusps of the teeth fitting together.
It is rare that the patient is aware of such change or discrepancies between the upper and lower jaw, and in many cases, such discrepancies are discovered by the dentist, dental technician, etc. in the course of designing dentures. Specifically, when dentists, dental technicians, etc. design dentures, after models of both the upper and lower jaw have been prepared based on impressions taken from the patient, a specialized device referred to as an articulator is used to place the upper and lower jaw models in a centric position and in a position with the cusps of the teeth fitting together in order to determine the discrepancy between the upper and lower jaw.
In cases where the discrepancy between the upper and lower jaw is extremely small, there is no particular problem with leaving this discrepancy untreated, but in cases where the discrepancy is great enough to exceed the allowable range, a burden is applied on the temporomandibular joint during chewing, and there may be a risk of causing damage to the jaw, such as temporomandibular disorder, it is preferable to carry out occlusal therapy at an early stage whenever possible.
In the past, however, as there was no way to allow the patient to easily observe the status of the discrepancy between the upper and lower jaw, e.g., the direction and amount of this discrepancy, this constituted a severe drawback with respect to the patient's informed consent to treatment, so the condition was left untreated.